Recommended Posts

I am new to this forum and have just purchased a 2000 Avalon, this car appeared not to have been well serviced of late and has done 275k.

I thought it was best to change oil and filters and used the recommended fully synthetic 5W 30.

Drove the car a couple of times and was ok, the next trip the oil light came on when idling but went out under acceleration, the next time I started vehicle the light would not go out, I changed the oil pressure switch hoping this was the problem but it was not.

A mechanic friend told me to Start the car without the oil pressure switch and I should expect quite an oil flow if it was ok, I did this and all that came out was a trickle.

So I am hoping that the problem might be the oil pickup in the sump has become blocked, or maybe the oil pressure switch gallery blocked?.

Link to post

Share on other sites

Based upon the information provided, my best guess is that the engine is sludged up due to inadequate servicing. The new oil with its detergent additives may have loosened and dissolved a fair bit of this sludge. I would be looking at whether the oil is badly contaminated i.e. dark black colour. Something else I have done is to use a thick diameter plastic straw and probe around inside the valve cover to estimate how badly sludged up the engine is.

After doing the above, I would then drop the oil pan and checking/cleaning the oil pickup screen.

If the engine is badly sludged up, definitely recommend removing the valve covers and cleaning the valve train and valve covers.

Next step would be reassemble then run [idle only] the engine with about 5 litres of diesel for about 5-10 minutes. Repeat if necessary.